Free online tools.

Create fantasy names in woodland, arcane or celestial styles, or combine English adjectives and nouns into nicknames. Filter by length and generate a complete downloadable list.

Time card calculator

Work out hours and pay after taking out unpaid breaks.

Percentage difference calculator

Compare two values without picking a starting point.

Roman numeral converter

Convert numbers to Roman numerals. Or the other way round.

Square footage

Calculate rectangular floor area in square feet and square meters.

Compress PDF

Make image-heavy PDFs smaller. Keep your text and page layout.

Invoice generator

Create a basic PDF invoice with your line items and tax.

Microphone test

Check the input level from your microphone.

Random word generator

Draw real English words from a disclosed curated list, filtered by part of speech and letter count, with optional uniqueness and complete list downloads.

Time duration

Work out the hours between two times, with breaks taken out.

Loan payment

Estimate monthly payments on a fixed-rate loan.

Margin

Calculate profit and profit margin from cost and selling price.

Percentage change

Calculate the percentage increase or decrease between two values.

Slope calculator

Find the slope, rise and run between two points.

Volume calculator

Calculate the volume of a box, cylinder, or sphere.

Compress video

Reduce a video's file size with an adjustable quality setting.

GCF calculator

Find the greatest common factor of a list of integers.

Lcm

Find the least common multiple of whole numbers.

PNG to PDF

Gather your PNG images into a single PDF.

Stopwatch

Measure elapsed time and take lap readings.

Average

Find the mean, median, sum, minimum, and maximum of a list of numbers.

Keyboard test

Check which key and modifier signals your browser receives.

Online notepad

Write plain-text notes and download a copy.

Pace calculator

Find your pace, finish time or distance, with kilometre and mile splits.

Palette generator

Build a family of lighter and darker shades from one color.

PDF to PNG

Turn PDF pages into PNG images you can use elsewhere.

Standard deviation

Calculate the mean and standard deviation of a set of numbers.

Base64 encoder decoder

Encode text as Base64, or turn Base64 back into readable text.

Lorem ipsum

Generate placeholder paragraphs for layout testing.

Pythagorean theorem calculator

Find a missing side of a right triangle.

Compare text

See what changed between two versions, line by line.

HEIC to PNG

Turn your HEIC photo into a PNG you can use anywhere.

Hourly to salary

Estimate annual and monthly gross pay from an hourly rate.

Quadratic formula calculator

Solve a quadratic, including complex and repeated roots.

Read aloud

Listen to written text while you read along.

Salary to hourly calculator

Turn annual pay into an hourly estimate.

Subnet calculator

Work out a subnet's address range and address count.

Binary to text

Decode binary byte values into UTF-8 text.

Business days

Count weekdays between dates, leaving out the holidays you enter.

Compress GIF

Reduce an animated GIF with palette and frame-rectangle options, retaining every frame and showing actual size and color changes.

Fuel cost calculator

Estimate the fuel bill before you leave.

HEIC to PDF

Convert the primary still image in a HEIC or HEIF file into a PDF with explicit paper size, page orientation and margins.

QR code reader

Read a QR code from an image or your camera.

Random letter generator

Pick random letters for games, prompts or practice.

Triangle

Calculate a triangle’s perimeter and area from its three side lengths.

Unix timestamp converter

Turn a Unix timestamp into a readable date, or convert a date back.

Bold text

Turn letters and digits into bold Unicode characters.

Discount

Calculate the saving and final price after a discount.

Flashcard maker

Create a small set of question-and-answer flashcards.

Pay raise calculator

See what a percentage raise means per hour and per year.

Case converter

Change capitalization without retyping your text.

Delete pages

Remove the PDF pages you do not need and save a new copy.

Small text

Convert supported letters into small-cap Unicode characters.

Blur image

Soften your image with an adjustable blur.

Flip image

Flip an image horizontally or vertically.

JSON validator

Find the syntax errors keeping your JSON from parsing.

Overtime calculator

Calculate regular pay, overtime pay and their total.

Random team generator

Split a list into balanced, randomly assigned teams.

Resize GIF

Resize every frame of a GIF with optional aspect-ratio locking while preserving frame count, delay values and playback count.

Temperature

Convert between Celsius, Fahrenheit, and Kelvin.

XML formatter

Format XML for reading or minify it for a compact result.

Barcode reader

Read a supported barcode from an image or your camera.

Collage maker

Arrange your images in a simple collage.

Email signature generator

Create a simple HTML email signature with your contact details.

Markup

Calculate profit and markup from cost and selling price.

Mph to kmh

Convert miles per hour to kilometers per hour.

Regex tester

Try a JavaScript regular expression and see what it matches.

Sentence counter

Count sentences using English text segmentation.

Trim audio

Keep the part of a recording you want and cut the rest.

URL encoder decoder

Encode a URL component or make its encoded characters readable again.

UUID generator

Generate UUIDs when you need fresh identifiers.

Aspect ratio calculator

Find the simplest ratio for your image or screen dimensions.

Favicon generator

Give your site an ICO favicon made from an image.

JWT decoder

Read a JWT's header and payload without verifying its signature.

Markdown to PDF

Turn a Markdown document into a PDF you can share.

Ohms law

Calculate current and power from voltage and resistance.

RGB to hex

Turn red, green and blue values into a HEX color code.

Rounding

Round a number to a chosen number of decimal places.

Strikethrough text

Add a strikethrough mark to visible characters.

Subscript

Convert supported letters into subscript Unicode.

Superscript

Convert supported letters into superscript Unicode.

Circle

Calculate a circle’s diameter, circumference, and area from its radius.

Contrast checker

Check whether your text and background have enough color contrast.

Probability calculator

Calculate intersections, unions, complements and conditional probabilities for two events.

Utm builder

Add campaign tags to a link so you can tell your traffic sources apart.

Z-score calculator

See how many standard deviations a value sits above or below the mean.

Add days

Find the date a set number of days before or after another date.

Create PDF form

Create a PDF with text fields people can fill in.

Date difference

Find out how much time separates two dates.

Midpoint calculator

Find the point halfway between two coordinates.

Rotate PDF

Turn selected PDF pages the right way up.

Sharpen image

Make edges clearer with adjustable sharpening.

SQL formatter

Lay out your SQL queries so they are easier to follow.

Title case

Capitalize the first letter of every word.

Upside down text

Flip text into an upside-down Unicode style.

Weighted average calculator

Find the average when some values count more than others.

Crop PDF

Trim the visible margins around selected PDF pages.

Distance formula calculator

Measure the straight-line distance between two points.

Extract emails

Find unique email-like addresses in pasted text.

Extract ZIP

See what is inside a ZIP and extract its files.

Flatten PDF

Turn filled form values into fixed PDF page content.

JSON diff

Find added, removed and changed values between two JSON documents.

Passphrase generator

Generate a random phrase made of words for your next password.

PDF to text

Pull selectable text out of a PDF so you can copy and edit it.

Reverse text

Reverse the order of visible characters.

Rotate image

Turn your image by 90, 180 or 270 degrees.

Sample size calculator

Plan completed responses and invitations for a proportion or mean, with stated confidence, precision and population assumptions.

STL viewer

Preview an STL mesh and inspect its dimensions.

Weight

Convert between kilograms, pounds, ounces, and other mass units.

Word art generator

Give your words display lettering with font, fill, outline and layout controls.

Confidence interval calculator

Calculate two-sided t, z or Wilson confidence intervals from summary statistics.

Extract pages

Keep the PDF pages you need in one new document.

HTML to image

Turn HTML into an image you can use outside the page.

Italic text

Turn Latin letters into italic Unicode characters.

Merge video

Join clips into one video with a consistent frame size.

SVG to JPG converter

Turn a vector drawing into a ready-to-use JPG.

Circle crop image

Crop a centered circle and download a transparent PNG.

Color palette from image

Pull a palette of dominant colors from an image.

Combinations and permutations calculator

Count selections, with or without order.

Compress audio

Export audio as an MP3 at your chosen bitrate.

DPI converter

Set an image's print resolution without changing its pixels.

Image to STL

Turn a still image into a closed binary STL height-map relief with millimeter dimensions, a flat base and bounded sampling.

JSON to CSV

Turn JSON records into a CSV you can open as a table.

JSON to schema

Create a starting JSON Schema from sample data.

Line counter

Count all lines and nonempty lines in your text.

Merge audio

Join audio clips in the order you choose.

Power

Convert between watts, kilowatts, megawatts, and horsepower.

Prime factorization calculator

Break a whole number into its prime factors.

Split image

Cut an image into a set of smaller tiles.

Token counter

Estimate token usage with the selected tokenizer.

Coordinate converter

Convert decimal latitude and longitude to degrees, minutes and seconds.

Curved text generator

Bend text around an arc or circle with adjustable spacing.

Email header analyzer

Trace an email's delivery route and inspect authentication results.

Grayscale image

Take the color out and see your image in grayscale.

Length

Convert between meters, feet, inches, and other length units.

Reading time

Estimate reading time at your chosen pace.

Resistor color code

Find a resistor's value from its colored bands.

YAML validator

Find syntax errors that stop your YAML from parsing.

Color blindness simulator

Preview how colors may appear with different types of color blindness.

CSS flexbox

Create CSS for a flexible row or column layout.

CSS grid

Build CSS for a grid with your chosen columns and gaps.

CSV to excel

Give your CSV data an Excel workbook of its own.

Eml to PDF

Save an email's headers and plain-text message as a PDF.

Hex to text

Decode hexadecimal byte values into UTF-8 text.

PDF to markdown

Save selectable PDF text in a Markdown file.

Savings goal

Estimate the monthly contribution needed to reach a savings goal.

Speaking time

Estimate speaking time at your chosen pace.

Base64 to image

Turn Base64 image data back into a picture you can download.

Change audio speed

Change audio playback speed while preserving pitch.

Comma separated list

Turn nonempty lines into a comma-separated list.

Inspect file metadata

See what metadata an image file contains.

Number base converter

Move a number between binary, octal, decimal and hexadecimal.

Pronunciation player

Hear words and phrases with an available browser voice.

PX to REM converter

Convert CSS pixels and rem units in either direction.

Remove metadata

Make a fresh image copy without the original embedded metadata.

WEBP to PDF

Put WebP images together in a PDF document.

Wifi QR code

Put your Wi-Fi details in a QR code people can scan.

Add image border

Add a solid border without covering your image.

Add page numbers

Give your PDF page numbers so it is easier to navigate.

Change video speed

Speed up or slow down a video and its audio.

CSV to JSON

Turn CSV rows into JSON you can use in your next step.

CSV viewer

See your CSV as rows and columns instead of a wall of commas.

DPI calculator

Calculate pixel density from pixel count and physical size.

Extract tar gz

Extract the files inside a TAR or TAR.GZ archive.

Gradient generator

Build a two-color linear gradient and copy its CSS.

Javascript minifier

Reduce JavaScript file size without running the code.

Payment card checksum checker

Check the syntax and Luhn checksum of a card number locally. Results are masked. This does not verify a card, bank or payment.

XML to JSON

Change XML data into JSON without retyping it.

YAML formatter

Give your YAML consistent, readable formatting.

Annotate PDF

Add visible text where you need it on a PDF page.

Bubble text

Turn Latin letters and digits into circled characters.

Chmod calculator

Translate numeric Unix permissions into readable rwx flags.

Fill PDF

Fill in an existing PDF form with your own values.

HTML to text

Extract readable plain text from HTML markup.

ICO to PNG converter

Turn an icon file into a transparent PNG.

Image to base64

Turn an image into a Base64 string or data URL.

Invert image

Swap your image's colors for their opposites.

Javascript formatter

Make JavaScript easier to read without running it.

JSON schema validator

Check JSON against a schema and find the values that do not fit.

Markdown Table Builder

Turn tab-separated rows into an escaped Markdown table with alignment controls. Runs locally and returns a reviewable report.

Markdown to HTML

Turn your Markdown into HTML source, ready to review and use.

Password protect ZIP

Bundle files in a password-protected ZIP archive.

Remove background noise

Reduce steady background noise in an audio recording.

Robots txt tester

Check whether robots.txt rules allow a crawler to visit your URL.

Rotate video

Rotate a video by 90, 180 or 270 degrees.

Underline text

Add combining underlines to non-whitespace characters.

Week number calculator

Find a date's ISO week number and week-year.

CSS inliner

Move supported CSS rules into HTML elements for email templates.

Excel to CSV

Take one worksheet out of Excel and save it as CSV.

HTML to markdown

Strip back HTML markup into a Markdown document.

JSON escape

Escape text for a JSON string, or undo JSON string escapes.

JSON to excel

Give your JSON records an Excel spreadsheet.

Photo to line drawing

Create an edge-based line drawing from an image.

Text to HTML

Turn plain text into safe HTML paragraphs and line breaks.

Watermark PDF

Add a text watermark to the PDF pages you choose.

XLSX viewer

Open an Excel or OpenDocument worksheet as a readable table.

ASCII to text

Turn ASCII character codes into readable text.

Increase audio volume

Adjust audio gain with a limiter to control peaks.

Paragraph counter

Count paragraphs separated by blank lines.

Round image corners

Give an image rounded corners with a transparent background.

Sitemap generator

Create an XML sitemap from a public website's pages.

Vcard QR code

Share your contact details with a scannable vCard QR code.

Watermark image

Put a text watermark on your image before sharing it.

YAML to JSON

Turn YAML data into JSON for your next workflow.

Eml viewer

Open an EML file to read its message and see its attachments.

HTML escape

Escape HTML characters, or turn escaped entities back into text.

Schema generator

Build structured data markup for a web page.

Break even

Find how many units cover your fixed and variable costs.

CIDR to range

Expand a CIDR block into its first and last IP addresses.

Email QR code

Create a QR code that starts an email with your details filled in.

Emoji picker

Find emoji by an English name or keyword.

Geojson viewer

Preview GeoJSON on a map and check its structure.

Recipe scaler

Resize your ingredient list for more or fewer servings, including fractions and mixed numbers.

Speed

Convert between meters per second, kilometers per hour, miles per hour, and knots.

STL to OBJ

Turn an STL mesh into an OBJ file for your next 3D workflow.

SVG optimizer

Trim SVG markup to reduce its file size.

Word frequency

Count word occurrences, starting with the most frequent.

Area

Convert between square meters, square feet, acres, and other area units.

CSS box shadow

Build a CSS shadow with the position and blur you want.

CSS formatter

Give your CSS consistent, readable formatting.

CSS minifier

Reduce CSS file size by removing extra formatting.

Energy

Convert between joules, calories, watt-hours, and kilowatt-hours.

PDF metadata editor

Update a PDF's title, author, subject and keywords.

Redact image

Cover a rectangular area with a solid block.

SRT to VTT

Turn SRT captions into WebVTT subtitles for the web.

Threshold image

Convert an image to pure black and white.

URL parser

Break a URL into its host, path, query and other parts.

Volume

Convert between liters, milliliters, and US or Imperial volume units.

VTT to SRT

Convert WebVTT captions into an SRT subtitle file.

Whatsapp link

Create a WhatsApp chat link with a message ready to send.

APNG to GIF

Convert a validated animated PNG into a GIF while retaining animation frames and playback count, with explicit timing and transparency quantization.

Bulk resize images

Resize a batch of photos and download one ZIP.

Duplicate word finder

List repeated words and how often they appear.

Extract urls

Pull unique HTTP and HTTPS links out of a block of text.

Split CSV

Break a large CSV into smaller files, each with its header.

Subtitles to text

Take the words out of a subtitle file and leave the timecodes behind.

Accessible palette

Compare contrast between foreground and background colors in a palette.

Color shades

Find lighter and darker versions of your chosen color.

JSON to typescript

Start your TypeScript types from a sample of JSON data.

Jsonpath tester

Try a JSONPath expression and see which values it finds.

Merge CSV

Combine CSV files and line up columns by their headers.

Open graph preview

Preview the metadata that shapes your shared link.

Resize PDF pages

Fit your PDF onto the page size you need.

Screenshot capture

Capture an image of a screen or window you choose.

Bcrypt generator

Create a bcrypt password hash with your chosen cost factor.

Distance between coordinates

Find the surface distance between two map coordinates.

DOCX to markdown

Turn a Word document's text and structure into Markdown.

GPX to KML

Convert GPX track geometry and elevation to KML.

PDF to Base64 converter

Encode a PDF as Base64 text without changing its bytes.

Remove duplicate lines

Keep each line once and clear out the repeats.

Remove PDF metadata

Clear common document metadata from a new PDF copy.

Repeat text

Repeat text with a separator between copies.

Transcript editor

Edit your transcript alongside the original audio.

TSV to CSV

Turn tab-separated data into a comma-separated CSV.

IP range to CIDR

Express an IP address range as CIDR blocks.

ISBN checker

Check an ISBN-10 or ISBN-13 checksum, calculate a missing check digit, or convert between equivalent ISBN formats.

Pressure

Convert between pascals, kilopascals, bar, atmospheres, and psi.

Remove punctuation

Remove Unicode punctuation from your text.

RSA key generator

Generate a matching pair of RSA public and private keys.

Slug generator

Turn a title or phrase into a lowercase URL slug.

Time units

Convert between milliseconds, seconds, minutes, hours, days, and weeks.

URL to punycode

Convert international domain names to and from Punycode.

Create tar

Put your files together in a TAR archive.

CSV validator

Check CSV headers, quoting and row lengths before using the file.

Meta tag generator

Create HTML metadata for your page without writing each tag.

Pascal case

Turn words into a PascalCase identifier.

Wide text

Convert basic Latin characters to fullwidth Unicode.

Bates number PDF

Add a unique reference number to every PDF page.

Compress image to 100kb

Make an image fit a 100 KB limit. Reduce dimensions only if you choose to.

CSV to SQL

Build SQL statements from your CSV data.

Remove extra spaces

Clean up repeated spaces and keep your line breaks.

Sms QR code

Make a QR code that opens a prefilled text message.

Sort lines

Put your list in alphabetical or natural number order.

Split text

Split text at an exact separator, placing each part on a new line.

Adjust brightness

Lighten a dark image or bring the brightness down.

Angle

Convert between degrees, radians, and turns.

Create ZIP

Bundle your files into one ZIP that is easier to share.

HTML table to CSV

Take a pasted HTML table and save its data as CSV.

Ipv6 compress

Switch an IPv6 address between its short and expanded forms.

List archive contents

Check the names and sizes of files inside a ZIP.

Mock data generator

Create sample JSON records to test with.

Palette visualizer

See your palette on text, buttons and surfaces before using it.

Remove silence

Remove pauses below your chosen audio threshold.

Extract subtitles

Extract an embedded text subtitle track as SRT.

Jq playground

Filter and reshape JSON with a jq expression.

JSON to go

Build a Go struct from a sample JSON object.

JSON to java

Generate Java class definitions from sample JSON.

Quote generator

Turn your line items and tax into a PDF price quote.

Subtitles to PDF

Turn subtitle captions into a PDF transcript you can read.

Excel to HTML

Turn an Excel worksheet into an HTML table.

HTML to JSX Transformer

Convert common HTML attributes and inline styles to JSX and report embedded scripts for review. Runs locally and returns a reviewable report.

Subtitle editor

Fix subtitle text and timing, then save an SRT file.

Transcript search

Find phrases and related passages in imported timestamped transcripts.

Compare CSV

Find what changed between two CSV files.

CSV to TSV

Change CSV data into tab-separated rows.

Jsonl to JSON

Collect JSON Lines records into one JSON array.

Ods to XLSX

Move an OpenDocument spreadsheet into an Excel workbook.

Serp preview

See how your page title and description could look in search results.

SQL to CSV

Extract tabular data from SQL statements into CSV.

Trim text

Remove spaces from the start and end of each line.

Adjust image contrast

Adjust the contrast between light and dark areas.

Clean subtitles

Clear formatting tags, extra spaces and empty cues from subtitles.

CSV to geojson

Turn latitude and longitude columns into GeoJSON points.

Data storage

Convert between bits, bytes, decimal storage units, and binary storage units.

Geojson to CSV

Take GeoJSON properties and coordinates into a CSV table.

HMAC generator

Create a keyed authentication code for a message.

JSON to TOML

Convert JSON data into TOML configuration.

Merge subtitles

Bring subtitle files together on one timeline.

Split file

Divide a file into smaller parts of the size you choose.

Alternating case

Alternate lowercase and UPPERCASE letters.

HTML accessibility checker

Find missing image descriptions and labels in pasted HTML.

Join text

Join lines with a separator of your choice.

Shift subtitles

Move every subtitle earlier or later to match your video.

Change CSV delimiter

Change your CSV separator without manually replacing every comma.

Event QR code

Put calendar event details into a QR code.

JSON to python

Turn a sample JSON object into a Python TypedDict.

CSV join

Join CSV tables using a column they have in common.

Hreflang generator

Create hreflang tags for language and regional versions of a page.

CSV remove duplicates

Remove repeated CSV rows and keep the first copy of each.

Curl to code

Turn a cURL command into request code you can adapt.

Extract phone numbers

Find possible phone numbers in pasted text.

File hash

Calculate a file's hash and compare it with the value you expected.

JSON to TSV

Turn JSON records into tab-separated rows.

List combinations

Generate every combination from groups of items.

PDF header footer

Add a header and footer to every PDF page.

Tabs to spaces

Replace each tab with a fixed number of spaces.

Bulk rename

Give files a shared prefix and a clean sequence of numbers.

CSV pivot

Turn CSV rows into a grouped summary table.

Join files

Reassemble split file parts in filename order.

Pages per sheet

Fit several PDF pages on each output sheet.

Remove line numbers

Remove common numeric prefixes from lines.

3D print shrinkage compensator

Turn a measured test print into a scale correction. Compare all three axes or use one uniform reference dimension.

3D printing cost calculator

Estimate the cost of a print batch from filament, electricity, machine hours, labor and fixed overhead.

Accounts receivable turnover calculator

Compare credit-sales turnover and collection days across your financial periods.

Acronym inventory

Review uppercase abbreviation candidates against simple explicit definitions and your known-abbreviation list.

Adjust image saturation

Make colors more vivid or turn them down.

Advertising break-even calculator

Work out the most you can spend on ads for each order and still break even, from your order value, product cost, shipping and payment fees. See break-even and target CPA, ROAS, ACoS and cost per click.

Agreement analysis

Compare paired measurement methods using differences, agreement limits and a separate confidence interval for mean bias.

Airline Baggage Fee Comparison

Calculate from explicit travel assumptions locally.

Alternate merge PDF

Combine front and back scans in alternating order.

ANOVA comparison workspace

Compare 2 to 20 group means with one-way ANOVA, Welch's ANOVA and Tukey, Games-Howell or adjusted pairwise follow-up comparisons, or run a two-way ANOVA with Type II or Type III sums of squares.

Apache rewrite rule tester

Run your .htaccess or virtual host rewrite rules against test URLs and see the redirect, internal rewrite or error each one gets, with every rule and condition that matched.

API documentation drift checker

Compare the parameters your Markdown API reference documents with an OpenAPI or Swagger contract and find missing, extra and mismatched parameters and undocumented operations.

API example coverage checker

Find API endpoints that have no request example in your Markdown documentation, and examples that call endpoints the contract does not list.

API pagination merger

Merge uploaded page exports into one record array with duplicate detection, explicit conflict handling and source provenance.

Appliance electricity cost calculator

Calculate a transparent home-energy estimate locally from the assumptions you enter.

ARIA Relationship Checker

Find broken ARIA label, description and control references in HTML. Runs locally and returns a reviewable report.

Asphalt calculator

Estimate material quantities locally from dimensions, waste and explicit material assumptions.

Ass to SRT

Turn ASS subtitles into SRT captions with text and timing.

Assignment randomization engine

Write each question once as a template with number ranges, and get up to 50 versions where every student sees different numbers but the same kind of question, each with an exact answer key.

Autocorrelation diagnostic

Inspect lag dependence with an autocorrelation chart, pointwise white-noise references and explicit independence limitations.

Baggage Allowance Calculator

Calculate from explicit travel assumptions locally.

Baker's percentage calculator

Convert your recipe weights to baker’s percentages and scale every ingredient to a new total flour weight.

Baking tin lining template

Create a full-size base and side-strip pattern for a round or rectangular tin, with a tiled printable PDF.

Balance transfer calculator

Compare keeping a credit card balance where it is with moving it to a promotional card. See the transfer fee, the interest on each path, the payoff month and what the transfer saves or costs with the same monthly payment.

Balloon payment calculator

Work out the balloon left on a loan when regular payments stop before the loan is fully repaid. See the monthly payment, the interest paid, the balloon amount and the final payment, with the full schedule.

Baluster spacing calculator

Find the minimum number of balusters and equal gaps for your opening. Download every edge and center position to mark out the layout.

Bandwidth delay product calculator

Estimate in-flight data from bandwidth and round-trip time, with an optional receive-window comparison.

Battery cycle cost calculator

Calculate a transparent home-energy estimate locally from the assumptions you enter.

Bayes theorem visualizer

Update a prior from stated likelihoods and see every branch of the expected-frequency tree.

Bicycle fit dimension worksheet

Record your inseam and your bike’s saddle, crank, handlebar and frame measurements, and compare your saddle height with two published rules. It is a worksheet, not a bike fit, and makes no health claims.

Bicycle gear calculator

Compare bicycle gearing, gear inches, development and cadence across your chainrings and cassette.

Binary file comparator

Compare two local files byte by byte and download the changed offset ranges.

Blind size worksheet

Turn three width and three drop measurements per window into order sizes for recess-fit and face-fit blinds, with your blind maker’s deductions and overlaps. Out-of-square windows are flagged before you order.

Bolt circle calculator

Generate equally spaced hole-centre coordinates from a circle diameter. Set the first angle, numbering direction and centre offset.

Bonus pool allocation calculator

Split a fixed bonus pool across employees by base pay, target percentage and rating, or by your own weights. Awards add up to the pool exactly, to the cent.

Boolean logic truth tables

Build complete truth tables, classify formulas and compare logical equivalence with counterexamples.

Box plot comparison

Compare groups with documented quartiles, whiskers and outlier rules while keeping all observations in the report.

Bread dough temperature calculator

Estimate water temperature for your desired dough temperature, or calibrate friction from a measured batch.

Brick calculator

Estimate material quantities locally from dimensions, waste and explicit material assumptions.

Brine concentration calculator

Calculate salt from water weight, keeping salt-to-water and salt-to-total-solution percentages clearly separate.

Bundle price calculator

Price a product bundle by discount, fixed price or target margin, and see how the bundle price is shared across items with different margins. Spot items that lose money inside the bundle.

Business card maker

Compose and preview both sides of a contact card, with physical size, bleed and safe-area controls, then download an RGB print PDF, PNGs and editable source.

Byte order mark editor

Inspect, add or remove a UTF byte order mark without changing the encoded payload.

Caesar cipher encoder and decoder

Shift letters to create or solve a simple cipher puzzle.

Cake pan conversion calculator

Scale batter between round and rectangular pans using internal dimensions, fill depth and pan count.

Cake serving calculator

Estimate complete cake portions from your preferred serving dimensions and get a grid or wedge cutting plan.

Candle wax calculator

Calculate wax and fragrance from a measured container fill, with a clear wax-relative fragrance percentage.

Caption Coverage Checker

Compare speech and caption time ranges and expose missing intervals. Runs locally and returns a reviewable report.

Car lease calculator

Work out a monthly car lease payment from the price, residual value, money factor or APR, fees and your own tax rate. See the depreciation fee, rent charge and tax in each payment and the total cost of the lease.

Car ownership cost calculator

Add up what a car really costs over the years you plan to keep it: depreciation, loan interest, insurance, maintenance, fuel or electricity and other running costs. See the cost for each year, the total and the cost per kilometre or mile.

Cash conversion cycle calculator

Connect inventory, collection and payable days to calculate your cash conversion cycle.

Cash runway calculator

Compare monthly cash balances, reserve breaches and funding timing across business scenarios.

Categorical association tester

Test association in a contingency table up to 20 x 20 with Pearson chi-square, Yates, the G test and Cramer's V, with expected-count checks and residuals. Fisher's exact test covers 2 x 2 tables and small larger tables, with a seeded Monte Carlo version for the rest, and McNemar's test covers paired yes/no data.

Change GIF speed

Speed up a GIF or slow it down while keeping the same frames and loop count.

Changelog generator from commits

Create an editable Markdown changelog from structured Conventional Commits. Include every supplied commit once and carry over breaking-change explanations.

Checksum manifest verifier

Check selected files against a SHA-256 manifest and report changes, missing files and unlisted files.

Churn calculator

Calculate customer churn and gross or net revenue churn separately for a consistent opening customer group.

CI matrix expander

Expand a GitHub Actions matrix into the exact list of jobs it runs. See which include entries changed each job and which combinations exclude removed.

Circle intersection calculator

Find where two circles meet and measure their overlap. Enter both centers and radii, then download the diagram and intersection coordinates.

Clock Reading Worksheet

Create a printable worksheet locally with a complete answer key.

Cloze Passage Worksheet

Create a printable worksheet locally with a complete answer key.

Code ownership coverage checker

Find files that no CODEOWNERS rule covers, files a rule leaves without owners, and rules that match nothing.

Coffee brew ratio calculator

Calculate coffee or water from a brew ratio, then check extraction using measured beverage mass and TDS.

Coffee dilution calculator

Work out concentrate and dilution water for a target measured coffee strength.

Color-Only Signal Checker

Review status designs for signals that may rely on color without text or symbols. Runs locally and returns a reviewable report.

Compare PDF

See where the extracted text of two PDFs differs, page by page.

Compost volume calculator

Work out bin capacity and split the material you need to add using your own volume recipe.

Concept map assessment

Compare a student concept map with your own, link by link. Each of your links is marked matched, mislabelled or missing, extra student links are listed, and the score rule is shown.

Concordance reader

Find every literal phrase or consecutive word sequence with its original surrounding context.

Conic section analyzer

Classify a second-degree equation in x and y as a circle, ellipse, parabola, hyperbola or degenerate case. Exact invariants, the center, axes, foci and vertices are reported.

Container environment diff

Compare two supplied environment exports locally. See added, removed, changed and unknown variables without displaying their values.

Continued fraction explorer

See the exact convergents of a fraction or decimal, and compare the error at each step.

Conventional commit checker

Check a Conventional Commit message and its declared release impact. Review header, body and breaking-change footer issues.

Coordinate Plotting Worksheet

Create a printable worksheet locally with a complete answer key.

Correlation comparison

Compare linear and rank associations with a scatterplot, Fisher uncertainty and seeded paired-bootstrap uncertainty.

Crochet stitch calculator

Fit complete crochet repeats to a target width using your swatch gauge, repeat size and non-repeat stitches.

Cron overlap detector

Find cron jobs that run at the same time, the busiest minute and jobs that start again before they finish, including what happens on daylight saving days.

Crop GIF

Keep one rectangle from an animated GIF. Crop every frame without losing its timing.

Cross-stitch fabric calculator

Convert a design in stitches into its physical size and the fabric cut size, with a margin on every edge.

Cross-stitch thread estimator

Estimate whole skeins for one color using stitch count, a measured thread sample and explicit strand assumptions.

Crown molding angle calculator

Get the miter and bevel settings for crown molding laid flat on a compound miter saw, and the miter for a nested cut, from the corner angle and the spring angle. Each piece gets its fence edge, miter and bevel direction and the side to keep.

CSR generator

Create a private key and a certificate signing request in your browser. Fill in the names, choose a key type and download the CSR for your certificate authority together with the private key, which never leaves your device.